typedef struct ListNode* ListNode;
struct ListNode* FindKthtOTail(struct ListNode* head,int K)
{
	ListNode fast = head;
	ListNode slow = head;
	while (K--)
	{
		if (fast)
		{
			fast = fast->next;
		}
		else
		{
			return NULL;
		}
	}
	while (fast)
	{
		fast = fast->next;
		slow = slow->next;
	}
	return slow;
}
